Kai Leng

Kai Leng is an agent for Cerberus who takes orders directly from the Illusive Man. In the Mass Effect novels, Leng is sent to locate and terminate Paul Grayson. He is the top Cerberus wet-works operative sent for assassinations.

Kai Leng, Cerberus's top assassin, was featured in the Mass Effect novels. Mass Effect 3 marks the first time he appears in a game. Early concepts gave him metal legs and hard armor, but this evolved into a stealthier appearance with a coat remincient of Thane's. His face and body kept a few cybernetic implants to imply he'd been modified since the events in the books to become even deadlier.